Worthwhile change always requires sustained effort. Getting from point A to point B is an uphill slog and has a tipping point--the point where just enough energy and will power is expended to get to point B. The tipping point comes late along the uphill pathway. To illustrate:
Tipping points are important because measured in effort they represent the maximal effort required to get to point B. From the the tipping point it's but a short distance to B, the goal. For example, I don’t decide to lose weight, join a gym and credibly say I’ve changed (psychologically perhaps, but not physically) until I reach that tipping point which is well along towards the goal. Understanding the factors involved in the tipping point could, in theory, lower the barrier to such a change.
Downhill change also has a tipping point, but it lies closer to the starting point A: